Catalytic hydrogenation process



Patented Nov. 22, 1938 UNITED STATES CATALYTIC HYDBOGENATION PROCESSWilbur A. Luier. Wilmington, Del assignor to E. I. du Pont de Nemours aCompany. Wilmington, Del., a corporation of Delaware No Drawing.

Application March 14, 1934, Serial No. 715,509. Renewed June 3, 1930. InCan- .Ilfla Ma! 11, 1931 19 Claims. (01. 280-438) This invention relatesto catalytic processes and more particularly to processes for the liquidphase hydrogenation of carbon compounds by means of metallichydrogenating catalysts.

This case is a continuation in part of my copending applications SerialNo. 456,299 filed May 27, 1930 issued June 26, 1934 as U. S. Patent No.1,964,000, Serial No. 559,487 filed August 26, 1931, and Serial No.629,754 filed August 20, 1932.

Considerable work has been done in the field of catalytic chemistry witha view to developing eflicient materials for the hydrogenation of suchunsaturated compounds as the oleflnes unsaturated fats and fatty acids,benzene and its derivatives and a large number of other compoundscontaining unsaturated functions, such as aldehydes, nitriles, amides,and heterocyclic unsaturated rings. Most of this work has been basedupon the classical discovery of Sebatier, that finely divided metallicnickel is capable of causing the union of hydrogen with these compounds.This method has been further expanded and supplemented by the work ofIpatiew on the application of high pressures to these reactions.Extensive research has been carried out heretofore with the result thatseveral difierent methods for the preparation of hydrogenation catalystshave been developed, the most common of which involve the precipitationand reduction of nickel or copper hydroxides or carbonates, reduction ofnickel or copper oxides prepared by ignition of the nitrates, anodicoxidation followed by reduction, heating to their decompositiontemperatures of certain organic salts of hydrogenating metals andelectrochemical deposition of the metals. Furthermore, various methodsof reduction have been proposed ranging from the ordinary dry reductionwith hydrogen to reduction in an inert liquid vehicle or in the presenceof the oil or other substance undergoing hydrogenation.

, As is well known, these catalysts have found extensive use in thecommercial hydrogenation of fats, oils and similar readily hydrogenatedsubstances. It has now been found, however, that in general catalystsprepared by the above methods, although ordinarily suitable for thehydrogenation of fats and oils, may be entirely inadequate for the morediflicult hydrogenation of such compounds as aldehydes, ketones, sugars,phenols, furfural and its derivatives, or benzene and pyridine and theirhomologs. Although many types of nickel and copmr catalysts have beenused for various liquid or vapor phase hydrogenations, so far as I amaware, a catalyst prepared by heating a double chromate of a nitrogenbase and copper to its decomposition temperature has not previously beenemployed for the hydrogenation or dehydrogenation of organic compounds.

This invention has as an object to carry out catalytic processes by theuse of highly eflicient copper chromite catalysts. A further object isthe provision of a process for the hydrogenation of carbon compounds inthe liquid phase by the use of highly ei'iicient hydroge'natlng metalcatalysts, prepared by heating a multiple salt or copper and a. nitrogenbase to its spontaneous decomposition temperature with or without asubsequent reduction by means of hydrogen. It is a specific object tocarry out the hydrogenation of organic compounds containing unsaturatedoxygen to carbon linkages by the use of copper chromite catalystsderived from a double chromate of ammonium and copper. A still furtherobject is to carry out the dehydrogenation of organic compounds capableof dehydrogenation employing this type of catalyst.

Other objects will appear hereinafter.

These objects are accomplished by the following invention which, in itsgeneral aspects, comprises the employment in hydrogenations anddehydrogenations of copper chromite catalysts such as those prepared byheating a double chromate of a nitrogen base and copper to itsspontaneous decomposition temperature, thereby converting the chromateto a chromite. This conversion constitutes a species of reduction sincethe valence of the chromium atom has been changed from a higher to alower value. This heating or ignition may be, but need not be,accompanied or followed respectively by the step of simultaneously orsubsequently reducing the resulting chromite with hydrogen.

Methods for the preparation of catalysts of this type have beendisclosed in my copending application, Serial No. 456,299 filed May 27,1930 and the theory of their formation has been thoroughly discussed.The methods therein disclosed in detail for nickel chromite catalystsare equally applicable to the preparation of copper chromite catalystswhich may be made from multiple chromates of copper with nitrogen basessuch as pyridine, aniline, methylamine, toluidine, diethylamine, and thelike. Thus, a very active copper chromite catalyst preparation is formedby the interaction of equimolecular proportions of copper nitrate andnormal ammonium chromate solutions, followed by ignition of theprecipitate. Basic copper ammonium chromate, as formed by theprecipitation, yields a complex mixture of copper oxide and copperchromite on ignition which is directly applicable to the liquid phasehydrogenation of a large number of unsaturated organic compounds. It hasbeen found that further improvements in the usefulness and efliciency oithe copper chromite catalysts may be obtained if carrier materials suchas kieselguhr, pumice. silica gel, charcoal, or other inert materialsare mixed with the precipitate of copper ammonium chromate and themixture ignited to form an catalyst supported on because of thepotential s ly of unreduced hydrogenating metal which may becontinuously activated under the conditions of hydrogenation. When badlypoisoned, the chromium oxide component of the catalyst facilitatesregeneration which is brought about by gentle ignition followed byreduction. Another advantage is that the materials of this inventionlend themselves very readily to compression into a form which may beused in a continuous operation wherein the liquid to be hydrogenated ispermitted to flow over the contact mass in the presence of hydrogenunder pressure. Copper chromite is readily briquetted with the ordinarytypes of pharmaceutical tablet machinery without injury to the porosityor activity of the catalyst. l

Copper chromite catalysts prepared by methods other than ignition of thechromate, as for example by precipitation or fusion methods, such as bythe precipitation and ignition of basic copper chromates or bycoprecipitation of copper and chromium hydroxides followed by ignition,may be employed in the processes of the present invention but in generalthey are not as eflective as the catalyst prepared by the methods givenabove.

It will be apparent that a continuous method of operation using thecatalysts of this invention offers many advantages over the usualautoclave process.

Having outlined above the general purposes of the invention thefollowing examples of the application of the catalytic materials hereindescribed to particular reactions are included for purposes ofillustration and not in limitation:

Example 1 Fifteen hundred grams of copper nitrate dissolved in 4 litersof water was mixed with a solution containing 1000 grams of ammoniumchromate in an equal volume of water. Ammonium hydroxide was added toneutralize the acidity developed during precipitation of the copperammonium chromate. The precipitate was washed by decantation, filtered,and dried, after which it was ignited at a temperature of 400 C. Theresulting copper chromite powder was employed for the hydrogenation ofesters without further treatment. One hundred fifty grams of ethylazelate and 15 grams of copper chromite, prepared as described, wereplaced in a shaking autoclave. Hydrogen was introduced until thepressure reached 8000 pounds per square inch. The mixture was heated to270 C. and agitated for four hours, after which the absorption ofhydrogen had ceased. On recovery and separa- Example 2 Copper chromiteprepared as described in Example 1 was extracted with 10% acetic acid,

' washed and dried. One hundred fifty grams of ethyl oleate and gramsofthe extracted copper chromite were agitated in a shaking autoclave at250 C. and under a hydrogen pressure of 4900 lbs. After two hourstreatment in this manner it was found thatthe ester had been convertedin 83% yield to ethyl alcohol and a mixture of oleyl and stearylalcohols.

Example 3 Twenty-six grams of barium nitrate and 218 grams of cupricnitrate are dissolved in 0.8 liter of water by heating to 70 C. Asolution of 126 grams of ammonium bichromate and 0.15 liter of 28%ammonium hydroxide in 600 cc. of water is added with stirring. Theprecipitate is filtered, dried and ignited at 400 C. The ignitionresidue is then extracted twice with 10% acetic acid, washed and dried.

In an alloy steel tube having a capacity of about 0.4 liter is placed252 grams (1.25 moles) of diethyl adipate (B. P. 144-145/29 mm.) and 20grams of copper chromite catalyst prepared as described above.

The tube is closed, made gas-tight, and secured in a suitable agitatingdevice. Connection is made with the hydrogen supply and hydrogen isintroduced until a pressure of about 2000 lbs. per square inch isreached. Agitation is started and the reaction system is heated asrapidly as possible to 255 C. Additional hydrogen is now admitted to atotal pressure of 3000 lbs. per square inch. The temperature ismaintained at 255 C. while hydrogen is introduced periodically tomaintain the pressure between 2500 and 3000 lbs. After 2-2.5 hours, therate of absorption of hydrogen becomes quite slow. At this point thetemperature is decreased to 240 C. and the hydrogenation is continueduntil hydrogen absorption is complete. The agitation is stopped and thetube closed ofl, cooled, and the pressure released. The contents aretransferred to a GOO-cc. beaker with the aid of four -cc. portions of95% alcohol. The catalyst is removed by filtering with suction and iswashed on the filter with four more 25-cc. portions of alcohol. Fiftycc. of 40% sodium hydroxide is added and the alcoholic solution isboiled for 2 hours under a reflux condenser. The solvent is distilledoff up to a temperature of 95 C. The residue is then transferred to anapparatus for the continuous extraction of liquids and is exhaustivelyextracted with ether. The ether is distilled and after the removal ofwater and alcohol the glycol is distilled under vacuum in a -250-cc.Claisen flask. The yield is 125 to 132 g., or 85 to 90% of thetheoretical amount. Hexamethylene glycol boils at 143-144 C. (bath at180 C.) under4 mm. pressure and melts at 41 to 42 C.

Example 4 Eleven grams of copper chromite promoted with barium preparedas described in Example 3 above was mixed with 140 grams of ethylphenylstearate and charged into a shaker autoclave. Hydrogen wasadmitted to a pressure of 3000 lbs. per square inch, and the mixture washeated to 260 C. and agitated for 3 hours, at the end of which timehydrogen absorption was complete. Recovery and separation of the productyielded about 90% of phenylstearyl alcohol.

Example 5 Four hundred twenty-eight grams of copper anhydrous ammoniawas added tothe solution with agitation during a period of 15 to 30minutes.

The precipitate was filtered, washed once on the filter and dried, afterwhich it was ignited at 500 C. The resulting copper chromite powder wasextracted twice by stirringit for 15 minutes each time with a solutionof 200 grams of glacial acetic acid and 1800 cc. of water. Afterextraction it was washed free from acid, filtered, dried, and screenedthrough a 20 mesh screen. Two hundred seventy-five grams of thiscatalyst and 4330 grams of ethyl hydroxystearate were placed in anautoclave and hydrogen was introduced to a pressure of 3000 lbs. persquare inch. The mixturewas then heated to 260 C. and agitated for 9hours, after which hydrogen absorption had ceased. The decrease insaponiflcation numberv of the ester during this treatment correspondedto hydrogenation of the carboxyl group while recovery and separation ofthe product yielded 19% stearyl alcohol and 58% octadecanediol.

Example 6 which it was ignited at 400 C. The resulting chromite wasthen-1 extracted ,twiceby stirring for-l5 minutes each time in asolution of l00'parts "of glacial acetic acid' and 900 parts of water.After extractiomthe chromite was washed free from acid, filtered anddried at C. and screened to-20 mesh size. Two hundred pounds of coconutoil having a saponification number of 260and 10' lbs. of copper chromiteprepared as described werecharged into an autoclave and the gaseousmixture consisting of 70% hydrogen and 30% nitrogen was admitted to apressure of 4500 lbs. per square inch. The charge was then heated to 240C. and agitated for 5 hours while the temperature was slowly increasedto 320 C. at which point it was held constant for 45 minutes. At the endof this time the saponiflcation number of the oil had been reduced to 3,equivalent to 99% hydrogenation of the carboxyl group. A yield of 88% ofcrude coconut oil alcohols was obtained which was found to contain 65%of a' mixture of alcohols varying between 6 and 18 carbon atoms.

Example 7 A catalyst consisting of copper chromite supported onkieselguhr was prepared exactly as described in Example 5 above, exceptthat 205 grams of kiesulguhr was added to the copper nitrate-chromicacid solution and kept in suspension by vigorous agitation duringprecipitation with ammonia. The catalyst thus prepared consisted ofcopper chromite supported on kiesulguhr, the two components beingpresent in equal weight proportions. Ten grams of the catalyst preparedas described and 200 grams of furfural were placed in a shaker autoclaveand hydrogen was admitted to a pressure of 1500 to 2500 lbs. per squareinch. The mixture was then heat- -chromite thus .furalwas shaken withhydrogen at a pressure ed to. 185 to C. and vigorously agitated 15minutes afterwhich hydrogen absorption was complete. Distillation of theproduct under reduced pressure yielded 90% of furfuryl alcohol.

Example 8 A copper chromite catalyst was prepared as follows: Atwo-molar solution of neutral ammonium chromate was added to an equalvolume of a two-molar solution of copper nitrate with stirring at atemperature of 25 C. Ammonium hydroxide was added to neutrality tolitmus and the precipitate allowed to settle. The liquor was decantedand the precipitate was washed 5 times by decantation with cold water,filtered, and dried at 110 C. The copper ammonium chromate thus obtainedwas ignited at 400 C. to drive of! ammonia and oxygen, therebyconverting the residue to a bluish black powder characterized as copperchromite.

A mixture consisting of 15 grams of copper prepared and 200 grams offurof 1800 lbs. per square inch and at a temperature 0. Hydrogenabsorption stopped after 2 hours. The liquid product was found bydistillation to contain 67 grams of furfuryl alcohol, 75 grams of higherboiling material, and 13 grams of unchanged furfurai.

The copper chromite catalyst prepared as described may, before use, bereduced with hydrogen at about 400 C. The resulting compositioncontaining reduced copper, copper oxide, and copper chromite may then beused in the, hydrogenation of. furfural' under the conditions given forthe non-reduced copper chtomite catalyst. I

Example 9,

for.

A copper-chromium oxide catalyst was prepared by igniting basic copperammonium chromate at 400 Ciand reducing the resulting copper chromite'inhydrogen at 300 to 350 C. for four hours.- Five grams of the catalystwas shaken with 300 grams of nitrobenzene at 150- C. under a hydrogenpressure of 1800 pounds. Aniline was formed quantitatively, the reactionbeing completed after three hours.

Example 10 Fifteen grams of copper chromite catalyst prepared asdescribed in Example 5 above, was mixed with 150 grams ofpara-nitrotoiuene, and the mixture was placed in a shaking autoclave.After heating the mixture to C. hydrogen was admitted to a pressure ofabout 2000 lbs. The mixture was then agitated while maintaining thehydrogen pressure between 1600 to 2600 lbs. At the end of 2.5 hourshydrogen absorption was complete and 87% of the para-nitrotoluene wasfound to be hydrogenated to para-toluidine.

In another experiment made exactly as described above,alpha-nitronaphthalene was hydrogenated in about 85% yield toalpha-naphthylamine in seven hours. Alternatively, nitrocompounds may behydrogenated to the corresponding aromatic amines in a continuous liquidphase process in which the nitrocompound is allowed to flow over agranulated copper chromite catalyst in an atmosphere of flowing hydrogeneither at atmospheric or elevated pressures, and at temperatures in thesame range as employed in the batch process.

described 'in Example 5 above, was mixed with 159 grams of methylisobutyl ketone and heated for one hour in a shaker' autoclave at 160 to170 C., under a hydrogen pressure of 2000 lbs. per square inch.Quantitative hydrogenation of the ketone occurred, the productconsisting of 95 to 97% methyl isobutylcarbinol distilling at 130 to 131C.

Example 12 Twelve and seven tenths grams of copperbarium chromiteprepared as described in Example 3, was mixed with 159 grams ofbenzaldehyde and agitated in a tube autoclave for 1.5 hours at 145 C.under 2000 lbs. hydrogen pressure. Re covery and separation of theproduct showed no benzaldehyde remaining, and a yield of 136 grams or85.5% of benzyl alcohol, the remaining 14.5% consisting of high boilingoils the principal constituent of which was benzyl benzoate. No toluenewas formed.

Example 13 Twenty grams of copper-barium chromite pre pared as describedin Example 3 was agitated with 240 grams of ethyl alphahydroxyisobutyrate under a hydrogen pressure of 2500 lbs. per squareinch. Hydrogen absorption was rapid at about 200 C. and the reaction wascomplete in about one hour. On distillation of the product there wasobtained a 91% panediol-1,2.

Example 14 A'charge consisting of 245 grams of salicyl aldehyde and 20grams or copper chromite catalyst prepared as described in Example 5,was placed in a shaking autoclave and agitated at 145 to 155 C. and 1800lbs. per square inch pressure for one hour. The products of reactionwere taken up in ether and the catalyst removed by filtration. The etherwas evaporated and 300 grams of benzene added. Upon chilling thesolution 130 grams of salicyl alcohol crystals were obtained. A secondcrystallization after the addition of petroleum ether yielded anadditional 33 grams of salicyl alcohol. The total yield of 163 gramscorresponded to 65% of theory. Upon distillation of the residue therewas obtained 45 grams of unreacted salicylaldehyde.

In a similar manner, anisaldehyde, vanillin,

piperonal, and phenylacetaldehyde may be hydro- I genated over copperchromite catalysts to give as the products anisyl alcohol, vanillylalcohol, piperonyl alcohol and phenylethyl alcohol.

Although in the above examples certain definite conditions oitemperature, pressure, amounts of material, durations of reactions,etc., have been indicated, it is to be understood that any and all ofthese may be varied widely within the scope of the invention since theparticular conditions of operation are governed largely by the specificreaction catalyzed, the materials treated, and the catalyst selected fora given reaction. Thus, the temperature used for hydrogenation may varyfrom 50 C. to the decomposition temperature oi the substance beingtreated under the conditions or the reaction. Thus temperatures as highas 400 C. may be employed for the more stable organic compounds. Thereaction may be conducted at ordinary pressure or at increased pressureeven up to 700 atmospheres or more. The hydrogenation reactions may becarried out either in batch or continuous processes.

It will be apparent from the examples given that the catalysts or thisinvention have many yield of 2-methylprovaluable applications. Althoughtheir use in certain selected liquid phase hydrogenations have beendescribed in illustration of particularly advantageous properties, theyare capable 01 use broadly in many types of hydrogenations as well as indehydrogenations in the liquid phase. Thus, copper chromite catalystsare particularly well suited to the hydrogenation oi unsaturated organiccompounds wherein the unsaturation represents a deficiency of hydrogenin a carbonoxygen or nitrogen-oxygen bond. Hence, copper chromitecatalysts are especially applicable to a type of unsaturation which maybe termed oxygen-unsaturation, and the full advantages of the inventionflow from the hydrogenation with copper chromite catalysts of organiccompounds containing unsaturated oxygen atoms. Several types or organiccompounds contain such oxygenunsaturation. First, there are thenitro-com- 'pounds, which, as the examples show, are readilyhydrogenated to the corresponding amines. The nitro-compounds may be ofeither aliphatic or aromatic type. Theinvention is applicable to thehydrogenation of nitrobenzenes, nitrotoluenes, nitronaphthalenes,methoxynitronaphthalenes, nitrophenols, nitroanilines, etc. The secondlarge class of oxygen-unsaturated carbon compounds are the carbonylcompounds typified by the aidehydes and ketones. The process of thepresent invention is applicable to aliphatic and aromatic aldehydes andto aliphatic, aromatic and mixed ketones. Thus through hydrogenationwith copper chromite, benzaldehyde is converted to benzyl alcohol,acetaldehyde to ethanol, butyraldehyde to butanol, acetone toisopropanol, methyl isobutyl ketone to methyl isobutyl carbinol, etc.Substituted aromatic aldehydes such as p-toluic aldehyde, vanillin,piperonal, salicyl aldehyde, etc. are converted smoothly into thecorresponding substituted aromatic alcohols. Other types oi!oxygen-unsaturated organic compounds are represented by the large classof carboxylic acids, esters, amides, and salts, several cases of thehydrogenation of which are disclosed in the examples. In this connectionit is to be noted that many organic hydrogenation reactions represent anequilibrium in which the product of hydrogenation, unless continuouslyremoved from the reaction zone, undergoes dehydrogenation. In this typeof reaction there are present three compounds, namely, a compoundcapable of hydrogenation, a compound capable of dehydrogenation andhydrogen. The catalysts of this invention are not only effective incausing the reaction to proceed in the direction of hydrogenation butalso under the proper conditions to induce dehydrogenation.

As indicated by the examples, copper chromite may be prepared by anumber of methods within the scope of the invention. Ordinarily it ispreferable to start with copper nitrate and prepare the catalyst asdescribed in Example 5, but for reasons of economy other copper saltssuch as copper sulfate may be used provided precautions are taken toeliminate poisonous impurities from the finished catalyst. Acidextraction of the copper chromite is advantageous in many cases but maybe avoided in special cases, such as the hydrogenation of furfural,without sacrificing catalytic efficiency. Improved activity and physicalproperties, and economic utilization of the catalyst may be effected bysupporting it upon a carrier such as kieselguhr, and it is sometimesadvantageous particularly in the hydrogenation of esters and furfural toincorporate small amounts of an alkaline buil'er such as barium oxide ormagnesia to counteract the effect of acidity which is sometimesdetrimental both to the catalyst, and to the stability of the reactants.

Unlike nickel chromite, it is unnecessary that copper chromite beprereduced before use in a hydrogenation reaction although it may bedone without detriment to the catalyst if desired.

Although the use of copper chromite has been described for the most partin certain liquid phase batch hydrogenations it is also capable of usein a continuous liquid phase hydrogenation as well as in dehydrogenationreactions in either vapor or liquid phase.

As many apparently widely diiierent embodiments of this invention may bemade without departing from the spirit and scope thereof, it is to beunderstood that I do not limit myself to the specific embodimentsthereof except as defined in the appended claims.

I claim:

1. The process of hydrogenating an unsaturated oxygen-to-carbon linkagecapable of hydrogenation of an organic compound containing same, whichcomprises bringing said compound in the liquid phase in contact withhydrogen in the presence of a catalyst prepared by heating a multiplechromate of a nitrogen base and cop.- per to its spontaneousdecomposition temperature.

2. The process in accordance with claim 1 characterized in that thereaction is carried out at a temperature of at least C.

3. The process in accordance with claim 1 characterized in that theprocess is a continuous flow liquid phase process and the catalyst is ina granulated briquetted form.

4. The process in accordance with claim 1 characterized in that thenitrogen base is ammonia.

5. The process of hydrogenating an unsaturated oxygen-to-carbon linkagecapable of hydrogenation of an organic compound containing same, whichcomprises bringing said compound in the liquid phase in contact withhydrogen in the presence of a catalyst prepared by heating to itsspontaneous decomposition temperature a multiple chromate of a nitrogenbase and copper which is supported on a substratum.

6. The process in accordance with claim 5 characterized in that thenitrogen base is ammonia.

7. The process oi hydrogenating an unsaturated oxygen-to-carbon linkagecapable of hydrogenation of an organic compound containing same, whichcomprises bringing said compound in the liquid phase in contact withhydrogen in the presence of a catalyst prepared by heating to itsspontaneous decomposition temperature a multiple chromate 01' a nitrogenbase and copper supported on kieselguhr.

8. The process in accordance with claim 7 characterized in that thereaction is carried out at a temperature of at least 50 C.

9. The process in accordance with claim 7 characterized in that thenitrogen base is ammonia.

10. The process of hydrogenating an unsaturated oxygen-to-carbon linkagecapable of hydrogenation oi an organic compound containing a same, whichcomprises bringing said compound in the liquid phase in contact withhydrogen in the presence of a catalyst comprising essentially copperchromite prepared by igniting a double chromate of a nitrogen base andcopper.

11. The process oi hydrogenating an unsaturated oxygen-to-carbon linkagecapable of hydrogenation of an organic compound containing same, whichcomprises bringing said compound in the liquid phase in contact withhydrogen in the presence of a catalyst comprising essentially copperchromite prepared by precipitating copper chromate in the presence ofammonium hydroxide and heating the resulting precipitate to itsspontaneous decomposition temperature.

12. The process of hydrogenating an unsaturated oxygen-to-carbon linkagecapable of hydrogenation of an organic compound containing same, whichcomprises bringing said compound in the liquid phasein contact withhydrogen in the presence of a catalyst prepared by heating a multiplechromate of a nitrogen base and copper to its spontaneous decompositiontemperature and thereafter reducing the resulting composition inhydrogen.

13. The process 01 hydrogenating an unsaturated oxygen-to-carbon linkagecapable of hydrogenation of an organic compound containing same, whichcomprises bringing said compound in the liquid phase in contact withhydrogen in the presence of a catalyst formed by reacting in aqueoussolution substantially equimolar proportions of a copper salt andammonium chromate, adding ammonia to neutralize the acidity developedduring the precipitation, washing, filtering, drying and igniting theprecipitate by heating it to its spontaneous decomposition temperatureand thereafter reducing the resulting composition in hydrogen.

14. The process of hydrogenating an unsaturated oxygen-to-carbon linkagecapable of hydrogenation of an organic compound containing same, whichcomprises bringing said compound in the liquid phase in contact withhydrogen in the presence of a catalyst formed by reacting in aqueoussolution substantially equimolar proportions of a copper salt andammonium chromate, adding ammonia to neutralize the acidity developedduring the precipitation, washing, filtering, drying and igniting theprecipitate by heating it to its spontaneous decomposition temperature,extracting the ignited precipitate withacetic acid, and thereafterreducing the resulting composition in hydrogen.

15. The process of hydrogenating an unsaturated oxygen-to-carbon linkagecapable of hydrogenation of an organic compound containing same, whichcomprises bringing said compound in the liquid phase in contact withhydrogen in the presence of a copper chromite catalyst.

16. The process or claim 15 characterized in that the organic compoundis a carbonyl compound.

17. The process oi claim 15 characterized in that the catalyst issupported on a substratum.

1B. The process of claim 15 characterized in that the catalyst issupported on kieselguhr.

19. The process of claim 15 characterized in that the process is acontinuous-flow liquid phase process and the catalyst is in a granulatedbriquettcd form.

WILBUR A. mm.

